google/syzkaller

syzkaller is an unsupervised coverage-guided kernel fuzzer

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Summary Information

Updated 28 minutes ago
Added to GitGenius on September 10th, 2026
Created on October 12th, 2015
Open Issues & Pull Requests: 628 (+0)
GitHub issues: Enabled
Number of forks: 1,446
Total Stargazers: 6,320 (+0)
Total Subscribers: 179 (+0)

Repository Insights (GitGenius)

Median issue/PR response: 4.3 hours
Mean response time: 54.3 days
90th percentile: 76.2 days
Tracked items: 448

How this project is maintained

Around half of the issues opened in the past year never receive a reply. Only 16% of open issues come from outside the core team — the tracker reads mainly as internal planning. 74% of tracked open issues have had no activity in three months, so the open count overstates what is actively being worked. Only 5% of issues opened in the past year have been closed. Three people close 85% of everything that gets resolved.

Charts & Analytics

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Issue Activity (beta)

Open issues: 275
New in 7 days: 3
Closed in 7 days: 2
Avg open age: 556 days
Stale 30+ days: 258
Stale 90+ days: 238

Recent activity

Opened in 7 days: 3
Closed in 7 days: 2
Comments in 7 days: 2
Events in 7 days: 4

Top labels

  • enhancement (278)
  • bug (207)
  • AI patching (84)
  • syzbot user request (17)
  • syzbot ci (14)
  • research (8)
  • help wanted (7)
  • os:linux (7)

Detailed Description

syzkaller is a coverage-guided kernel fuzzer that automatically discovers bugs in operating system kernels through unsupervised fuzzing.

The tool addresses the challenge of finding security vulnerabilities and stability issues in kernel code by generating and executing randomized system call sequences. It uses coverage feedback to guide its fuzzing strategy, meaning it tracks which code paths have been exercised and prioritizes generating new inputs that reach unexplored areas of the kernel. This approach is more effective than random testing because it systematically explores the kernel's behavior space rather than blindly hammering it with arbitrary inputs.

Syzkaller is suited for kernel developers, security researchers, and maintainers who need to identify bugs before they reach production. It works across multiple operating systems and architectures, making it applicable to projects maintaining kernels or kernel-adjacent code. The tool is particularly valuable for continuous integration pipelines where automated fuzzing can run alongside traditional testing to catch edge cases and race conditions that manual testing might miss. Organizations with security-focused development practices benefit most from integrating syzkaller into their testing infrastructure.

The project maintains active development with regular commits addressing new kernel features and fuzzing strategies. The codebase receives ongoing refinement to improve crash detection and reporting accuracy. The tool continues to evolve with enhancements to its coverage instrumentation and input generation heuristics. Development activity shows sustained attention to expanding support for additional kernel subsystems and architectures.